If you just want to see the docstring for a function you're using, just mouse-over the function and wait a second before a pop-up pops up with the help. You can press F2 to give the pop-up focus so you can resize and scroll it.

Download the html version of the documents and add them to your project, it works good, except for context help beyond param lists.
According to Sourceforge feature request, there are several requests for this dating back to 2006, sounds like an opportunity to jump in and help.